The role of hydroxyapatite coating in joint replacement surgery - Key considerations

The use of a porous hydroxyapatite (HA) coating has definitively increased the durability and biocompatibility of joint replacement prostheses (JRP) since its introduction. This article will contextualise the properties of porous HA and relate these characteristics to its clinical function. Novel strategies to encourage osseointegration will also be explored, alongside their clinical relevance. All major literature databases were scrutinised for literature relevant to the scope of our review. The role of Hydroxyapatite was evaluated, alongside further strategies to augment bone ingrowth. HA coatings remain the most optimal coating for widespread clinical use. Advantages are conferred due to the method of application, the tribology and the biocompatibility of the material. Further strategies are available to augment bone ingrowth, pertaining to biological modifications and implantation of external factors. An evaluation of the literature has described the relative long term performance of the HA coated JRPs both in isolation and when compared with cemented prosthesis. Metanalyses have shown HA coated JRPs to perform as well as cemented prosthesis in terms of survivability over both short and long term follow ups. Concerning strategies to augment osseointegration, consideration should be given to form and function of the coating surface, as this provides the basis for cell adherence, proliferation, and differentiation.